Guidelines for Trimming Clematis Plants

Project Summary

• Overall Duration: 1 hour

• Proficiency Level: Intermediate
• Projected Expense: $0

Clematis plants, which encompass both climbing and spreading types, are known for their vibrant, large blossoms. Cultivating these plants is relatively straightforward, yet many gardeners feel apprehensive about the pruning process. This apprehension is unfounded, as the key to pruning lies in understanding the blooming schedule of your clematis. Similar to other large-flowered garden plants, clematis vines are typically pruned to promote fresh growth and an abundance of blooms. If pruning is neglected, the growth and new flowers will be limited to the tips of the vines.

Requirements

Gear / Instruments

• Bypass secateurs

Materials

• Garden refuse bag

Instructions

Clematis can be categorized into three primary groups for the purpose of pruning:

• Group 1 consists of plants that blossom in early spring, utilizing growth from the previous year (old wood). Their flowering period concludes by mid to late spring. Notable varieties in this category include cultivars of C. armandii, C. montana, and C. apina.
• Group 2 consists of plants that flower in spring and early summer. They generate blooms on both last year’s growth and on new shoots. Many of these are hybrids known for their large flowers. This category features varieties of the well-liked Clematis patens species.
• Group 3: This category blooms on new growth from the current year during late summer and autumn. Notable examples include hybrid varieties like Jackman’s clematis and ‘Ernest Markham.’

If you’re unsure about the pruning category of your clematis, observe the plant throughout the season to determine its blooming times and frequency.

Trim Early Spring-Blooming Clematis (Group 1)

This group of plants can often be left unpruned for several years without significant adverse effects. However, when you decide to prune, it’s best to do so right after they finish blooming in the spring. Since these plants produce flowers on older wood, allowing them ample time to grow for the following season is essential. Typically, this means pruning should be completed by the end of July. Start by cutting away any dead or damaged branches, then trim any overgrown outer stems back to the main woody stems or close to the ground. The extent of pruning ultimately depends on the desired shape of the plant.

Trim Clematis that flowers in spring and summer (Group 2).

Clematis varieties within this category typically showcase a vibrant display of flowers in the spring, followed by a lighter bloom later in the year. Regular annual pruning is crucial; neglecting this can lead to an imbalance in the plant, resulting in fewer flowers. In late winter or early spring, remove all damaged or dead stems all the way to the ground. For the remaining stems, cut them back to just above the strongest, most prominent buds. After the initial bloom period, trim back to a pair of buds located about halfway down the stems. This pruning technique can encourage a second wave of blooms on new growth in late summer or early autumn.

Trim Late-Flowering Clematis (Group 3)

The late-blooming category of plants generates blossoms on the growth of the current season, necessitating a distinct pruning strategy. These plants usually die back to the soil level during winter, and any remaining old growth can lead to a cluttered appearance. Therefore, during late winter or early spring, trim these plants back to approximately 2 feet above the ground. Many of these species are robust growers, occasionally approaching invasive tendencies, so it’s important to prune them vigorously and consistently each year.

The Optimal Time for Pruning Clematis Plants

The ideal timing for pruning clematis varies based on whether the plant blooms on last year’s growth or on the new growth of the current season. It’s important to avoid pruning in a way that would remove or diminish the blooms, as this is the primary reason for cultivating clematis.

Clematis types that flower on old wood should be trimmed right after their blooming period ends, allowing the plant ample opportunity to develop new stems for the upcoming season. In contrast, those that flower on new wood should be pruned while the plant is in a dormant state, ideally in late fall, winter, or very early spring, before the new growth starts.

Guidelines for Trimming Clematis Plants

Handle slow-growing plants with care, trimming only as much as necessary to achieve your desired shape. With faster-growing clematis, you can be more assertive with your pruning.

Additionally, feel free to postpone pruning responsibilities until you have observed a couple of growth seasons. Once you understand your plant’s growth patterns, it will be easier to determine the appropriate pruning approach to take.

Ultimately, it’s beneficial to retain several robust, mature stems, even for types that flower exclusively on fresh growth. These stems create a supportive structure that allows new growth to flourish.